The PI proposes to expand on previously published work of hers and develop a comprehensive semiparametric methodology for gene localization by linkage disequilibrium. The methods will be applicable to a variety of study designs and study populations. The proposed methods require only minimal assumptions about the population and the genetics of the disease and are computationally simple. Tools will be developed for validating the underlying assumptions of the model, for improving the gene location estimate and confidence interval given the model, and for providing guidelines as to the requirements and limitations of the methods in realistic genetics settings.